The Neuroprotective Effect of Lamotrigine and Interferon Beta 1a in Patients With Relapsing-Remitting Multiple Sclerosis

Inclusion Criteria: * definitive multiple sclerosis according to Mc Donald criteria * clinical isolated syndrome according to Mc Donald criteria * Expanded Disability Status Scale Score 0-5 * Pre-treatment with interferon beta 1a (Avonex) since at least 2 months before inclusion Exclusion Criteria: * relapse within 30 days prior to randomisation * steroid pulse therapy within 30 days prior to randomisation * pregnancy or poor contraception * contraindication for lamotrigine * depressive symptoms * drugs with possible interaction with lamotrigine according to instruction leaflet * other medical relevant conditions but multiple sclerosis * clinically relevant laboratory results * contraindication for MRI * missing informed consent